Dopefish fad
The not-so-sucessful Dopefish fad was created by Black Squirrel not long after he joined the forums. The idea was simply to put some form of dopefish in your avatar or signature, a creature from the Apogee DOS game Commander Keen 4: Goodbye Galaxy.
A dopefish is a green fish which lives in the Shadowlands. It eats practically everything, and is regarded as unintelligent (Hence the 'dope' in it's name). It's lack of intelligence means that it only repeats the phrase "Swim swim HUNGRY". Only appearing in one level in CK4, the Dopefish have since started a cult throughout the internet and have appeared in Apogee's later games as cameos. Occasionally they are also spotted in games not developed by Apogee too.
The fad was sucessful for a few days, but due to many members not knowing what a dopefish was, it wasn't as popular as some fads.